Capacitance boundary-based single-end all-line quick-action protection method of power distribution line

Abstract

The invention discloses a capacitance boundary-based single-end all-line quick-action protection method of a power distribution line. By the capacitance boundary-based single-end all-line quick-action protection method, internal and external in-phase faults of the power distribution line can be rapidly and reliably identified, and relatively high transition resistance capability is achieved. A parallel capacitor at each bus of the power distribution line is used as a boundary component for steady-state distribution compensation and transient-state fault identification, a fault transient-state voltage characteristic is limited in a fault line by a reflection effect of the capacitor on a step fault travelling wave, the transient-state energy difference of a voltage time domain during the internal and external faults is analyzed and extracted by a small wave, and the configuration of an all-line quick-action protection scheme is achieved by comprehensively considering current amplitude characteristic before and after the faults. By the capacitance boundary-based single-end all-line quick-action protection method, current weak protection configuration of the power distribution line is favorably improved, and a protection foundation is provided for a power distribution system containing a large amount of distributed power supplies.

Description

technical field [0001] The invention belongs to the technical field of electric power system relay protection, and in particular relates to a single-end full-line rapid protection method for distribution lines. Background technique [0002] Distribution network protection is the guarantee for the safe and reliable operation of the distribution network. Accurate and rapid detection and isolation of faults are of great significance to improve the reliability of power supply and the quality of power consumption of users. my country's distribution network is mostly radial with a single power supply, the grid structure is weak, and the protection configuration is simple, with three-stage current protection as the main protection. The current protection is based on the power frequency current. Although the setting principle is simple and easy to implement, it needs to cooperate step by step and cannot protect the entire length of the line. The protection range is greatly affected ...

AI Technical Summary

Problems solved by technology

The distribution network has short lines, many branches, low voltage, no obvious fault boundary, and the fault characteristics inside and outside the area are quite different from those of the high-voltage system; and the existing research on the full-line fast protection of distribution lines is mainly based on communication means, using longitudinal The principle realizes the full-line quick-action function, so the single-ended full-line quick-action protection of distribution lines that does not rely on communication needs to be further studied

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